The biochemical effects of extracellular Zn 2+ and other metal ions are severely affected by their speciation in cell culture media

摘要: Investigations of physiological and toxicological effects metal ions are frequently based on in vitro cell culture systems, which cells incubated with these specialized media, instead their environment. This allows for targeted examination the cellular or even molecular level. However, it disregards one important aspect, different ion speciation under conditions. study explores role conditions investigations zinc (Zn2+). Their concentration is buffered by several orders magnitude fetal calf serum. Due to complexity serum its many zinc-binding components, media cannot be completely predicted. Still, primary effect due main Zn2+-binding protein albumin. Buffering reduces free Zn2+ concentration, thereby diminishing biological effects, such as cytotoxicity impact phosphorylation. not limited Zn2+, but also observed Ag+, Cu2+, Pb2+, Cd2+, Hg2+, Ni2+. Usually, content buffering capacity, only a fraction that leads systematic over-estimation extracellular when standard used model systems assessing potential vivo effects.